Which weight of oil to run in 2.8l?

[WVHick]

I was looking in the owners manual, but it has this stupid temperature chart that's impossible to decipher. I live in WV, where in winter, it can get down to 0 and even below on rare circumstances. In the summer, it can get up to 100 degrees. Should I run 0w40 year around?

[ianwpb]

0-40 would work just fine year around.

http://www.my-gti.com/2534/ for further reference. I use Castrol Syntec/edge 5W40, but as you see 0-40 is approved with a ton of other oils. Castrol is readily available at almost all autoparts stores.

[bondar1989]

Run 5w40 total quartz 9000 and don't look back. here you go.http://www.europaparts.com/oil-chang...2-8l-3-0l.html

[EErie B6]

5w-40 would be fine too (and might be easier to find)

[WVHick]

Awesome. Thanks, sirs.

[teleTay]

i use mobile 1 5w-40

[miggity02]

shell rotella t6 5w40.

[EErie B6]

shell rotella t6 5w40.

http://www.audizine.com/forum/showth...I-ZERO-add-oil

[FNK]

I currently run 5w-40 oil in my 2.8 30V... however the oil temp is around 225F on the highway at 115kph... what I want to try is some 5w-30 next. If the temp stay at 200F like it's supposed to, then this would mean the heat is much better transfered.
Yes the oil film will not have the same thickness, but it will be 25F lower too, so it should be almost the same cinetic viscosity.

I am currently working on some Tribology problems, I will come up later with an approximation of the film thickness.

[FNK]

Interesting results, indeedidly!!

At 100C, the viscosity of the 5w-30 and 5w-40 are respectively 12.0 and 14.5 cST. [centiStoke, or 10E-2 mm²/s]

Using 5w-40, my engine oil reach the temperature of 225F constantly on the highway.
The Viscosity at 225F or 107C is now 12.4 cST.

If the use of 5w-30 lower the operating oil temp to 200F or 94C.
The viscosity would be of 13.7 cST. The film would be superior in viscosity using 5w-30 oil vs the 40 weight! So, Lower pumping loses, lower heat, more mpg and power...!?

A more probable result would appear to be a lowered oil temperature to 212.5F. At this temp, the viscosity is about the same as the 40 at 225F, 5w-30 at 212.5= 12.0 cST.
Considering the friction would be about the same with the oil at the same viscosity, but lower temps, an operating temp of 212.5F is therefor quite logical.

I will be able to confirm this in the next two weeks when I'll have the time to change my oil from 5w-40 to 5w-30.

5w-30
200F=13.7
212.5=12.0
225=10.4
237.5=9.0

5w-40
200F=16.7
212.5=14.5
225=12.4
237.5=10.7